1. Field of the Invention
The present invention relates to signal monitoring systems and methods used for checking and controlling apparatuses such as electronic equipment, and particularly to a signal monitoring system and method that can monitor plural signals by only employing a single data bus.
2. Description of Prior Art
Generally, an electrical system can be wired so that various monitoring signals such as voltage signals or temperature signals are generated. The monitoring signals correspond to measurements of various critical functions of the electrical system, which are determined according to practical requirements. A good example is the temperature of a central processing unit (CPU) in a personal computer system. The temperature should be monitored in order to prevent the CPU from overheating and failing, for example when a fan on the CPU malfunctions. A signal monitoring system is provided to fulfill the above-mentioned object. The signal monitoring system generally includes a temperature sensor for measuring the temperature of the CPU, generating temperature signals, and transmitting the temperature signals to a monitor chip via a data bus. Thereupon the monitor chip may send a control signal to shut down the CPU in order to prevent the CPU from overheating.
The above-mentioned signal monitoring system can include a plurality of sensors for monitoring a plurality of functions and for transmitting corresponding generated signals to the monitor chip via a respective data bus. The signals may, for example, be one or more voltage signals. FIG. 3 is a simplified block diagram of hardware infrastructure of the above-mentioned signal monitoring system. The signal monitoring system includes a plurality of sensors 110, 120, 130, 140, a plurality of data buses 210, 220, 230, 240, and a monitor chip 300. Each of the sensors 110, 120, 130, 140 is electrically connected to the monitor chip 300 via a respective one of the data buses 210, 220, 230, 240. The sensors 110, 120, 130, 140 generate signals, and transmit the signals to the monitor chip 300 via corresponding data buses 210, 220, 230, 240. The monitor chip 300 processes the signals generated by the sensors 110, 120, 130, 140.
The above-mentioned signal monitoring system is capable of monitoring plural signals by employing the plurality of data buses 210, 220, 230, 240. Each of the data buses 210, 220, 230, 240 connects one of the sensors 110, 120, 130, 140 with the monitor chip 300. That is, the monitor chip 300 can only control a particular class of signal via a respective single data bus. As a result, the more sensors there are, the more data buses are needed for transmitting the signals generated by the sensors. In practice, this means that the number of classes of signals that the monitor chip 300 can process is limited. Consequently, a signal monitoring system and method that can monitor plural signals by only employing a single data bus is desired.